1. Field of the Invention
The present invention relates to substrate processing equipment and, in particular, to multi-chambered processing equipment for use in manufacturing semiconductor devices or the like. More specifically, the present invention relates to structure used to create a seal between a chamber, such as a process chamber, and a transfer chamber of multi-chambered substrate processing equipment.
2. Description of the Related Art
Semiconductor devices are generally manufactured by selectively and repetitively performing various processes on a substrate, namely a semiconductor wafer. These processes typically include a photolithography process, an etch process, a diffusion process, a chemical vapor deposition process, an ion implantation process, and a metal deposition process. Of these processes, the etch process, the chemical vapor deposition process, and the metal deposition process are performed by injecting process gas into a sealed process chamber and exciting the process gas with radio frequency (RF) power to produce plasma.
Known semiconductor device manufacturing equipment of the type that produces plasma includes multi-chambered cluster type of equipment having a plurality of process chambers. The process chambers are integrated so that a plurality of wafers can be processed simultaneously to maximize efficiency in the manufacturing of today's highly integrated semiconductor devices.
More specifically, the multi-chambered equipment includes a central transfer chamber in which a robot is disposed, one or two loadlock chambers at one side of the transfer chamber, and a plurality of process chambers at the other side of the transfer chamber. In addition, the semiconductor device manufacturing equipment has coupling structure by which the loadlock chamber(s) and the process chambers are connected to the central transfer chamber.
The coupling structure of the multi-chambered equipment includes a plurality of O-rings interposed between the contacting surfaces of the chambers so as to establish a seal therebetween. However, the seal is continuously affected by the plasma generated in the process chamber. That is, the structure connecting the transfer chamber and the process chamber is exposed to the plasma generated in the process chamber. The O-rings are particularly susceptible to being damaged by such plasma.
If the O-rings were damaged, gas could leak into or from the process chamber thereby altering the processing conditions in the chamber, i.e., causing processing errors and defects in the product produced in the chamber. Therefore, at present, the O-rings are periodically replaced before they have a chance to become damaged. Specifically, the O-rings are replaced as part of a preventive maintenance (PM) program in which the equipment is also cleaned.
However, the O-rings need to be replaced frequently to prevent them from being damaged by the plasma. Hence, the frequent need to replace the O-rings dictates that the PM be performed frequently. Accordingly, the processes being carried out in the process chambers are frequently interrupted to implement the PM program, which interruption detracts from the productivity of the equipment and contributes to high production costs.